Biological reduction of carbon dioxide pollutants systems and methods

ABSTRACT

Methods and systems to achieve clean fuel processing systems in which carbon dioxide emissions ( 1 ) from sources ( 2 ) may be processed in at least one processing reactor ( 4 ) containing a plurality of chemoautotrophic bacteria ( 5 ) which can convert the carbon dioxide emissions into biomass ( 6 ) which may then be used for various products ( 21 ) such as biofuels, fertilizer, feedstock, or the like. Sulfate reducing bacteria ( 13 ) may be used to supply sulfur containing compounds to the chemoautotrophic bacteria ( 5 ).

PRIORITY CLAIM

This application is a continuation of United States National Stageapplication Ser. No. 13/127,697 filed May 4, 2011, which claims priorityto and the benefit of International Application Number PCT/US2010/043392filed Jul. 27, 2010 which claims priority to and the benefit of U.S.Provisional Application No. 61/228,898 filed Jul. 27, 2009 and U.S.Provisional Application No. 61/358,700 filed Jun. 25, 2010, each herebyincorporated by reference herein.

This application relates to work performed under U.S. DOE CooperativeAgreement #DE-FC26-08NT43293. The U.S. government may have certainrights in this inventive technology, including “march-in” rights, asprovided for by the terms of U.S. DOE Cooperative Agreement Numbers DOE#DE-FC26-08NT43293.

TECHNICAL FIELD

This invention relates to the technical field of clean processingsystems, specifically, methods and apparatus for capturing andconverting carbon dioxide emissions from fossil fuel consumption sourcesor other industrial carbon dioxide emitters. Through perhaps the use ofchemoautotrophic bacteria, the invention provides apparatus and methodsthat can be used to capture and reduce carbon dioxide emissions into theatmosphere.

BACKGROUND OF THE INVENTION

Carbon sequestration is a topic receiving enormous attention in themedia and among government agencies and industries involved in fossilfuel production and use. Combustion of fossil fuels is responsible forapproximately 83% of greenhouse gas emissions in the U.S. Currently, theU.S. emits 6.0×10⁹ tons carbon dioxide per year and this value isexpected to increase by 27% over the next 20 years. Furthermore, thereported link between increasing concentrations of greenhouse gases suchas carbon dioxide (CO₂) in the atmosphere and global climate change hasprompted several countries to adopt environmental standards that cap CO₂emissions and aim to reduce current emissions. Although the U.S. has notadopted a similar set of standards, in April 2007, the U.S. SupremeCourt ruled that carbon dioxide was a pollutant and that the U.S.Environmental Protection Agency (U.S. EPA) has the authority andobligation to regulate carbon dioxide emissions from automobiles.Recently, the U.S. EPA has decided that carbon dioxide poses a threat tohuman health and the environment and that it will now be added to a listof 5 other greenhouse gases that can be regulated under the Clean AirAct. Given recent activity regarding carbon dioxide emissionregulations, it is projected that the federal government may enact acarbon cap-and-trade bill. When this eventually occurs, utilitycompanies and coal producers are in a position to be particularlyaffected by federal carbon dioxide regulation due to the large carbondioxide footprint of coal-fired power plants. Although no carbon dioxidestandards have been applied to power plant emissions in the U.S., plansfor dozens of new coal-fired power plants have either been scrapped ordelayed due to issues revolving around states concerned with futureclimate change legislation. Whether there is global consensus on thecauses of climate change or not, it appears that carbon dioxide-emittingindustries in the U.S. will soon be required to implement carbonmanagement protocols that reduce emissions and (or) purchase or producecarbon credits.

The present invention seeks to aid the United States in the pursuit ofEnergy Security in an environmentally safe manner. An objective of thepresent invention may be to set the stage for achieving the vision of“Clean Coal” by turning carbon dioxide into a valued resource ratherthan a costly expense and long-term liability risk. In addition to coal,embodiments of the present invention have applications in carbon dioxidecapture for fossil fuel conversion sources, natural gas-fired powerplants and perhaps even distributed generation fuel cells, as well.Solving the carbon dioxide challenge for both coal and natural gas mayassure the commercial viability of United States energy industries in acarbon constrained world and in turn may secure the Nation's economicprosperity.

Subsurface injection of carbon dioxide (also termed “geological carbonsequestration”) has been considered as a default method for large-scalecarbon sequestration, even though the associate costs of carbon dioxideisolation and purification from flue gas, compressing, transportation,and injection are prohibitive, and little is known about the long termsustainability and potential environmental impacts. Thereforetechnologies that can achieve source capture and sequestration of carbondioxide is highly desired. Technically and economically, capture andconversion of carbon dioxide in proximity of emission sources, such aspower plants, can offer the most cost-effective model of sustainablecarbon sequestration.

Biological techniques as represented by microalgae reactors have beeninvestigated since the 1970s and are now implemented at pilot scale forcarbon dioxide capture and conversion to biomass. Although thealgae-based technology shows potential in carbon dioxide capture, it maybe limited by the light source (i.e. sunlight) for photosynthesis, theprimary carbon dioxide-fixation pathway in algae. Another limitation maybe the large area of land required to operate the photobioreactors.These obstacles, however, may be overcome by the bacterial reactor inthe various embodiments of the present invention. Bacteria may be thebest candidates in bio-trapping of carbon dioxide thanks to their highreproduction rate and ubiquitous distribution.

DISCLOSURE OF THE INVENTION

The present invention may provide biological carbon capture andconversion systems and methods to remove carbon dioxide from emissions.In embodiments, the present invention may integrate a carbon captureprocess into existing fuel combustion sources including combustion powerplants and natural gas fueled fuel cell plants as a biological carboncapture and conversion system to remove carbon dioxide from emissions.

The resulting biomass produced may be reprocessed as fertilizer,feedstock, fuel, biofuel, or the like or may even be directly injectedinto the combustion facility (such as perhaps in co-fired applications).It is a goal of the present invention to utilize carbon dioxide as avalue-added product of fossil-fuel power plants rather than aproduction-limiting waste product. In this way the carbon originallyreleased from coal combustion can be captured and recycled in perhaps aclosed-loop system, thus, significantly lowering overall carbonemissions and even improving plant efficiency.

It is another goal of the present invention, in embodiments, to enhanceeconomic and energy security of the U.S. through the development of atechnology that can reduce energy-related emissions of greenhouse gasand possibly improve the energy efficiency of power generation utilitiesand perhaps even to ensure that the U.S. can maintain a technologicallead in this field. Additionally, this concept may support many goals ofthe Administration's Energy and Environment Agenda including investmentin the next generation of energy technologies, producing more energy athome and promoting energy efficiency (perhaps through biofuel andco-fire applications for the biomass produced), closing the carbonloophole, and promoting U.S. competitiveness.

The impacts of embodiments of the present invention may provide utilitycompanies with an environmentally responsible and economically viablecarbon capture system. Furthermore, the utilization of this technologycan be relatively rapid compared to other options for carbon capturesuch as geologic sequestration which may still require years of testingand modeling as well as sophisticated site characterization and largecapital costs with each deployment to ensure injection activities do notcreate a legacy of potential liability for end users and futuregenerations of Americans. In addition to the potential for a relativelyrapid R&D phase, low risk to the end user in terms of long termliability, and the ability to improve plant efficiency through biofuelproduction and (or) co-fire applications, the biologic carbon capturesystem can almost certainly create new green jobs associated with thedesign, construction, maintenance and operation of these systems atpower plants across the country as well as spur increased activity andinnovation in the bio-processing/biofuel industries focused on utilizingthe enormous quantities of biomass that can be produced.

Naturally, further objects, goals and embodiments of the inventions aredisclosed throughout other areas of the specification and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a conceptual model of bacterial reactor system for carbondioxide capture and conversion into biomass in accordance with someembodiments of the present invention.

FIG. 2 shows a conceptual model of an overall biological carbon captureand conversion process in accordance with some embodiments of thepresent invention.

FIG. 3 is an example of a schematic summary of a chemoautotrophic CO₂capture Calvin Cycle in accordance with embodiments of the presentinvention.

FIG. 4 is an example of a conceptual model of the CAT biological carboncapture and bioproducts process in accordance with embodiments of thepresent invention.

FIG. 5 is an example of an integrated CO₂ Capture, CAT and Bioproductssystem diagram in accordance with embodiments of the present invention.

FIG. 6A is an example of catalytical transesterification in accordancewith embodiments of the present invention.

FIG. 6B is an example of a system dynamic modeling for marketpenetration in accordance with embodiments of the present invention.

FIG. 7 is an example of a schematic diagram of the drop-in CAT processintegrated into about 600 MWe power plant with the flow rate unit ofMlb/hr (the biomass conversion (e.g., the amount of CO₂ converted tobiomass) is assumed to be 95%) in accordance with embodiments of thepresent invention.

FIG. 8 is an example of a general system in accordance with embodimentsof the present invention.

MODE(S) FOR CARRYING OUT THE INVENTION

The present invention includes a variety of aspects, which may becombined in different ways. The following descriptions are provided tolist elements and describe some of the embodiments of the presentinvention. These elements are listed with initial embodiments, howeverit should be understood that they may be combined in any manner and inany number to create additional embodiments. The variously describedexamples and preferred embodiments should not be construed to limit thepresent invention to only the explicitly described systems, techniques,and applications. Further, this description should be understood tosupport and encompass descriptions and claims of all the variousembodiments, systems, techniques, methods, devices, and applicationswith any number of the disclosed elements, with each element alone, andalso with any and all various permutations and combinations of allelements in this or any subsequent application.

The present invention, may provide in various embodiments, methods ofreducing carbon dioxide pollutants and perhaps even processing systemsfor reduction of carbon dioxide pollutants. For example, a method mayinclude but is not limited to producing at least some carbon dioxideemissions from a carbon dioxide emittingsource; containing said at leastsome carbon dioxide emissions from said carbon dioxide emittingsource;efficiently introducing said at least some carbon dioxide emissions fromsaid carbon dioxide emittingsource into at least one processing reactor;chemoautotrophically digesting carbon dioxide of said at least somecarbon dioxide emissions with a plurality of chemoautotrophic bacteriain said at least one processing reactor; biologically producing at leastsome biomass from said chemoautotrophic digestion of said carbon dioxidewith said chemoautotrophic bacteria; and perhaps even ecologicallyreducing atmospheric release of said carbon dioxide emitted from saidcarbon dioxide emitting source. A system may include but is not limitedto a supply of at least some carbon dioxide emissions from a carbondioxide emittingsource; an emissions container configured to contain atleast some of said carbon dioxide emissions from said carbon dioxideemittingsource; at least one processing reactor configured to receivesaid at least some of said carbon dioxide emissions from said carbondioxide emitting source; a plurality of chemoautotrophic bacteria insaid at least one processing reactor configured to digest at least someof said carbon dioxide; an amount of biologically produced biomass bysaid chemoautotrophic bacteria located in said at least one processingreactor; and perhaps even an ecological reduction of atmospheric releaseof said carbon dioxide emissions.

Initial understanding of the present invention may begin with the factthat embodiments using chemoautotrophic bacteria perhaps even in abioreactor for carbon dioxide consumption may be combined with varioustechnologies such as but not limited to: fossil fuel consumptionsources, power generation source, cement producing plants, coalrefineries, oil refineries, refineries, lime producing plants, non-powergeneration sources, coal-fired power plants, natural gas-fired powerplants, generation fuel cells, combustion power plants, or the like.Fossil fuel consumption sources may include any type of system orapplication in which a fossil fuel may be consumed or perhaps evenconverted in the process. For example, coal is heated in cement plantsand power generation sources in the production of cement and energy andperhaps even crude oil may be converted into gasoline, diesel fuel,asphalt, or the like at refineries and the like. In embodiments, fossilfuel conversion sources may include any system or industrial system inwhich carbon dioxide is generated and emitted into the atmosphere.

Generally, chemoautotrophic bacteria, such as sulfur-oxidizing bacteria,may be a candidate species to fix carbon dioxide emitted from variousprocesses. Chemoautotrophic bacteria may utilize elemental sulfur,various sulfide minerals, sulfur containing compounds, or other productsas an energy source (e.g., electron donors) and carbon dioxide as theirprimary carbon source. Chemoautotrophic bacteria may efficiently oxidizesulfur containing compounds, sulfur and perhaps even sulfides, may fixcarbon dioxide, and may even produce biomass or perhaps even high cellbiomass as an end product. Chemoautotrophic bacteria (5) may be a carbondioxide emissions scrubber in which they may be utilized to scrub carbondioxide from emissions of fossil fuel consumption sources which may beconsidered a carbon dioxide capture technique for the purpose of meetingemission values imposed by cap and trade legislation or the like.

One example of a flow process representing various embodiments of thepresent invention is demonstrated in FIG. 1, where at least oneprocessing reactor (4) may be configured to receive and even processemissions such as raw flue gas from stack emissions from a fossil fuelconsumption source (2). A fossil fuel consumption source (2) may releaseemissions which may include a supply of carbon dioxide emissions (1) andother emissions (8) such as nitrogen, nitrogen oxide, sulfur oxide,oxygen, combinations thereof, or the like emissions. Carbon dioxideemissions may be efficiently introduced, perhaps even passing through aheat exchanger (32) for cooling of the emissions in some embodiments,into at least one processing reactor (4). Efficient introduction mayinclude filtering, channeling, flowing, directing, capturing, moving,transporting, connecting (either directly or indirectly) and the like ofemissions from a fossil fuel consumption source to at least oneprocessing reactor. A plurality of chemoautotrophic bacteria (5) may beincluded in at least one processing reactor to which the plurality ofchemoautotrophic bacteria (5) may be configured to chemoautotrophicallydigest carbon dioxide from the emissions. Chemoautotrophic bacteria mayinclude a plurality of bacteria of the same species or may even includea plurality of bacteria from more than one species of bacteria and maybe carbon fixing bacteria and sulfur oxidizing bacteria, such as but notlimited to A. ferrooxidans, Sulfolobus spp., and combinations thereof.These biologically based carbon dioxide capture technologies may utilizenatural occurring reactions of carbon dioxide within living organismslike chemoautotrophic bacteria. Carbon dioxide from emissions may beenzymatically transformed and integrated into the bacteria, thus carbonmay be stored in the cell biomass. The biologically produced endproductbiomass (6) may be dominantly amino acids, carbohydrates, and water. Itis noted that the chemoautotrophic bacteria may be utilized in variouscarbon dioxide capture technologies with or without a processing reactorand the chemoautotrophic bacteria may be supplied from any kind ofsource for use in these systems. In embodiments, a processing reactormay include any type of vessel, reactor, container, system, or the like.

An amount of biologically produced biomass (6) may be collected from atleast one processing reactor with a biomass collector (29). Inembodiments, a biomass collector (29) may include a continuous biomassremoval element for continually removing biomass from at least oneprocessing reactor such as but not limited to a concentrator,centrifuge, disk-stack centrifuge, or the like. The produced biomass maybe readily collected and removed from the reactor to allow recycling ofthe medium. Biomass (6) may be processed or even converted into aproduct (21) which may include but is not limited to methane, hydrogen,alcohol, fertilizer, feedstock, bioenergy, food, biofuel, biodiesel,military fuels, ethanol, plastics, animal feed, food amendments, or thelike; therefore, perhaps a sellable endproduct which can off-setoperational expenses or even generate surplus profit. The process may becost-effective in capturing carbon dioxide from emissions, let alone theside benefit from the biomass end product. The commercial value of thistechnology, perhaps when used in scaled up operations, could beunlimited.

A variable amount of biomass can be produced through this processdepending on the level of carbon sequestration required by the emissionssource; however, even modest amounts of carbon capture and conversionmay result in the production of massive amounts of biomass. The abilityof the Nation to become self-sufficient with sustainable energytechnologies is an essential aspect for achieving energy security and,in turn, economic security and prosperity. Our consumption rate ofdomestic coal may be slowed by feeding the biomass into the plant as afuel along with perhaps a smaller amount of coal. This may lengthen theduration that our domestic coal can be used to achieve energy security.Utilizing the biomass to produce transportation fuels may enablelessening import of foreign oil from Venezuela and the Middle East.

As mentioned above, the present invention may provide an energy supply(9) perhaps even a chemoautotrophic bacteria energy supply to aplurality of chemoautotrophic bacteria (5) which may be located in atleast one processing reactor (4). The energy supply (9) needed to drivebiological carbon fixation to the chemoautotrophic bacteria in this typeof reactor can be added, for example, as a supply of sulfur containingcompounds (16) such as metal sulfides, hydrogen sulfide (H₂S) or perhapseven elemental sulfur, of which there may be large stockpiles worldwideas this is a waste product of the oil refining process. Additionally, itmay be possible to recycle an energy supply to the chemoautotrophicbacteria with a recycled chemoautotrophic bacteria energy supply (10)within a system and perhaps even from a second processing reactor (11)which may generate the chemoautotrophic bacteria energy supply. In someembodiments, a recycled chemoautotrophic bacteria energy supply may berecycled from within the same processing reactor. A processing reactor,or in some instances a second processing reactor (11), may includesulfate reducing bacteria which could reduce sulfate generated by thechemoautotrophic bacteria to sulfides to which the sulfides can then beutilized by and even recycled to the chemoautotrophic bacteria as theirenergy supply. Sulfate reducing bacteria (“SRB”) may be a sulfur or evena sulfate reducing bacteria and may even include any bacteria that canreduce oxidized sulfur species. Thus, in embodiments, a secondprocessing reactor (11) may produce a supply of sulfur containingcompounds (16) and may even be a sulfate-reducing processing reactor. Asupply of sulfur containing compounds (16) may include elemental sulfur,sulfides, metal sulfides, hydrogen sulfide, or the like which can beconsumed by chemoautotrophic bacteria. Further, the sulfate-reducingbacteria may also produce biomass (6) which may be collected andprocessed as discussed herein.

Accordingly, in embodiments, recycling of an energy supply, for examplesulfur containing compounds, to the chemoautotrophic bacteria mayinclude providing sulfate reducing bacteria (13) in a second processingreactor (11), connecting (either directly or indirectly) at least oneprocessing reactor (4) containing the plurality of chemoautotrophicbacteria to the second processing reactor (11) containing the sulfatereducing bacteria with perhaps a connection (14), generating sulfate orother oxidized sulfur species (15) in the least one processing reactor(4) containing the chemoautotrophic bacteria (5), supplying sulfate oroxidized sulfur (18) from the at least one reactor (4) containing thechemoautotrophic bacteria to the second processing reactor (11)containing the sulfate reducing bacteria (13), generating sulfurcontaining compounds (16) in the second processing reactor (11)containing the sulfate reducing bacteria (13); and perhaps evensupplying sulfur containing compounds (19) from the second processingreactor (11) containing the sulfate reducing bacteria (13) to the atleast one processing reactor (4) with the plurality of chemoautotrophicbacteria (5) as may be understood from FIG. 1. In this embodiment, theat least one processing reactor (4) may be configured to generatesulfate or oxidized sulfur (15) (perhaps by the chemoautotrophicbacteria) and the second processing reactor (11) may be configured togenerate sulfur containing compounds or reduced sulfur (16) (perhaps bythe sulfate reducing bacteria) and the two reactors may be connected(14) (either directly or indirectly) so that the sulfate and sulfur, oreven the oxidized and reduced sulfur, can be supplied each other. Thetwo reactors may be physically apart from each other, may be connectedor even joined by a permeable membrane or the like as may be understoodin FIG. 2, or even any type of connection or attachment including butnot limited to tubes, flows, pipes, or the like. In other embodimentsthe contents of the two reactors may be combined into one reactor andperhaps even multiple processing reactors may be used.

Alternatively, a sulfate reducing bacteria energy supply (35) may beprovided to the sulfate reducing bacteria (13) which may include wasteorganic carbon, organic matter, recycled organic matter such as cellmass or other residual materials collected from the biomass orbyproducts of the sulfate reducing bacteria and recycled back to thesulfate reducing bacteria, combinations thereof or the like. The sulfatereducing bacteria energy supply (35) may be recycled within a system ormay even be supplied from an outside source. In this case, the energyinput to drive the sulfate reducing processing reactor could be in theform of waste organic carbon sources including but not limited to wastedairy products, returned milk, waste dairy byproducts, cheese whey,straw, woodchips, or the like. In other embodiments, a recycled processbiomass residue electron donor supply (45) may be supplied to thesulfate reducing bacteria such that recycled process biomass residue maybe used by the sulfate reducing bacteria as an electron donor supply.

In embodiments and as can be understood from FIG. 2, emissions from afossil fuel consumption source including carbon dioxide emissions (1)and perhaps even other emissions (8) as discussed herein may becontained as they exit the fossil fuel consumption source (2) perhapseven in an emissions container (3). An emissions container (3) mayprevent up to about 100% of the emissions, in particular carbon dioxideemissions, from entering the atmosphere and may transport the emissionsto at least one processing reactor (4). In other embodiments, a systemmay prevent up to about 65%, up to about 70%, up to about 75%, up toabout 80%, up to about 85%, up to about 90%, up to about 95%, up toabout 99%, and perhaps even between about 65% to about 100% of carbondioxide emissions from entering the atmosphere. An emissions containermay be a receptacle, filter, channel, pipe, enclosure, or the like. Inembodiments, emissions may be processed prior to being introduced intothe at least one processing reactor. An emission pretreatment element(31) may pretreat the emissions perhaps even minimally to separatecarbon dioxide from the other emissions. In this respect, an emissionpretreatment element (31) may be a carbon dioxide emission separator.After emissions may be treated in the emission pretreatment element(31), carbon dioxide may be sent (40) to at least one processing reactor(4) for carbon digestion as discussed herein.

A processing reactor (4) may contain a growth medium (27) which mayinclude but is not limited to bacteria, mineral salts, trace vitamins,enzymes, a commercially available enzyme for pH control, pH control(33), or the like. The growth medium (27) may have adequate retentionfor carbon dioxide thus providing a carbon dioxide retainer but othergases such as nitrogen may flow through with perhaps no solubility.Bacteria such as chemoautotrophic bacteria in the processing reactor maydigest carbon dioxide at a digestion rate which is up to or even equalto a carbon dioxide inflow rate into the processing reactor. This mayprovide for optimal operation.

As biomass (6) may be removed and collected from at least one processingreactor (4) and perhaps even from a second processing reactor (11) intoa biomass collector (29) it may contain both biomass (6) and water (37).Water (37) may be returned (39) back to the processing reactor(s) orotherwise recycled into a system. These may be separated out with aseparator (38) and may even be dried in a biomass dryer (22) to whichthe biomass may be further processed into various products (21) asdiscussed herein. In embodiments, the biomass may be injected or evenfed back into a fossil fuel consumption source with perhaps a fossilfuel consumption source system injector (25) perhaps as fuel for theconsumption source.

Embodiments of the present invention may also potentially extend thesupply of non-renewable fuel sources such as coal or the like. Biomassproduced in the processing reactor(s) may be processed into biofuel suchas biodiesel or perhaps even ethanol or can be co-fired with coal in thepower plant, then the carbon dioxide initially liberated from coalthrough combustion can be captured and re-combusted. This process canpotentially recycle the carbon dioxide several times, and thereby reducethe amount of non-renewable fuel required to meet a plant's energyproduction goals. Further, any undigested carbon dioxide (41) remainingin the processing reactor (4) may be recycled. For example, anundigested carbon dioxide recycling element (23) may recycle unprocessedcarbon dioxide (41) back into a system perhaps even back into the fossilfuel emissions or even into an emission pretreatment element (31) as canbe understood from FIG. 2. A processing reactor may discharge othergases such as nitrogen (34) and oxygen (36) from the reactor and releasethem into the atmosphere or otherwise release these byproducts. Inembodiments, waste products, impurities, contaminants or the like may beremoved from the processing reactors or system as well.

Embodiments of the present invention may achieve the vision of “CleanCoal” by turning carbon dioxide into a value-added product of coal-firedpower plants, as well as other fossil fuel based consumption systems,rather than a production-limiting waste product that needs to bedisposed of through costly processes (e.g., deep subsurfaceinjection/sequestration). As can be understood from the discussionabove, one concept of the system may include flue-gas injection, whichmay provide CO₂ from flue-gas, into an aqueous reactor wherechemoautotrophic bacteria such as carbon-fixing bacteria may pull carbonout of solution and may incorporate it into their biological tissues andlipids (e.g., carbon fixation), perhaps effectively capturing the carbondioxide and converting it into biomass that can be continually harvestedfrom the processing reactor. This biomass can potentially be reprocessedas fertilizer, feedstock, biofuel, or perhaps even directly injectedinto a combustion facility (e.g., co-fired applications) to offset theamount of coal needed to achieve the plant's Btu goals and, therefore,perhaps dilute other impurities in the flue gas such as NO_(x) andSO_(x) stemming from coal combustion. In this way the carbon originallyreleased from coal combustion can be captured and may even be recycledin a closed-loop system, perhaps, significantly lowering overall netcarbon dioxide generation and emissions perhaps allowing a plant tomaintain power production without exceeding allowable carbon dioxidelimits. Embodiments of the present invention may elucidate optimalconditions that maximize carbon assimilation rates of chemoautotrophicbacteria in a bacterial system which may include a two-part bacterialsystem as illustrated in FIGS. 1 and 2

There are many advantages to utilizing non-photosynthetic organisms,such as chemoautotrophic bacteria, for carbon capture including theability to operate in various parameters such as but not limited to alllatitudes and climates, 24 hours a day, and perhaps even in denselypopulated reactor tanks rather than operating only when and whereadequate sunlight may be available in ponds or transparent tubes thatmay require large amounts of surface area to achieve sufficientillumination for photosynthesis, temperature control systems, and evensupplemental lighting for 24-h operation. The need for adding heatduring the winter season in northern climates may be avoided withnon-photosynthetic organisms and the additional controls and design ofalgae-based systems may also add significant capital and maintenancecosts that can be significantly reduced in a simple chemoautotrophicbacterial growth tank that can be located underground to help eliminateexposure to the elements as well as reducing the overall processfootprint on site. Therefore, in embodiments, a processing reactor maybe operated in any climate, up to 24 hours a day, and may even contain adense population of chemoautotrophic bacteria.

In embodiments, optimal conditions (e.g., pressure, temperature, andpH), nutrient concentrations (if any), sulfur concentrations, sulfurspecies concentration, inorganic carbon concentrations (e.g., CO₂, HCO₃⁻, or CO₃ ²⁻ depending on pH), inorganic ion concentrations, bacterialcell densities, and the like can be determined for maximum carbonfixation rates of various species/strains of carbon fixing bacteria.Inorganic carbon may be introduced as pure carbon dioxide forpreliminary tests and then in simulated flue gas mixtures for moresophisticated tests that may also determine the lowest level of flue gaspurity (i.e., least amount of pretreatment required and largest costsavings) for efficient bacterial growth and subsequent carbon capture.As discussed above, the reactor may also be equipped with a disk-stackcentrifuge or similar device capable of continually removing biomassfrom the reactor at pre-determined cell densities to produce a bacterialpaste that can be used for determining the quality of the biomass andpotential applications such as biofuel production or use as a co-firedfuel for blending with coal.

Alternative embodiments of the present invention may include a multistepbiological and chemical process for the capture and conversion of carbondioxide and/or other sources of inorganic carbon, into organiccompounds, where one or more steps in the process utilize obligateand/or facultative chemoautotrophic microorganisms, and/or cell extractscontaining enzymes from chemoautotrophic microorganisms, to fix carbondioxide or inorganic carbon into organic compounds where carbon dioxidegas alone or in a mixture or solution as dissolved carbon dioxide,carbonate ion, or bicarbonate ion including aqueous solutions such assea water, or in a solid phase including but not limited to a carbonatemineral, is introduced into an environment suitable for maintainingchemoautotrophic organisms and/or chemoautotroph cell extracts, whichfix the inorganic carbon into organic compounds, with the chemosyntheticcarbon fixing reaction being driven by chemical and/or electrochemicalenergy provided by electron donors and electron acceptors that have beengenerated chemically or electrochemically or input from inorganicsources or waste sources that are made accessible through the process tothe chemoautotrophic microorganisms in the chemosynthetic reaction stepor steps.

Exhibit A Background of Alternative Embodiments of the Invention

The present invention may include a Chemoautotrophic (“CAT”)bacteria-based CO₂ consuming process for the production of biodiesel andother bio-based products. The CAT process can provide the energy sectorand industrial emitters with a carbon capture and conversion technologythat may produce salable products perhaps thereby turning anenvironmental hazard and expense (such as a greenhouse gas “GHG”) into avalued resource with the potential to significantly reduce or perhapseven eliminate all foreign oil imports. If all power plant CO₂ emissionsare converted to biodiesel such as perhaps to about 64 billion barrelsof biodiesel, then the domestic transportation fuel market could be wellsupplied providing the U.S. with a strong export product creating adouble benefit for the U.S. trade deficit. Power plant efficiency canimprove and the cost of electricity (“COE”) impact to Americans may bewell below the ARPA-E target of less than a 20% increase.

Summary of Alternative Embodiments of the Invention

A variety of bacteria can be developed and evaluated for CO₂ consumptionand the biomass precursor quality from which bio-oils may be extractedand end products produced. A two bioreactor system may be advanced tofacilitate reduction of SO₄ ²⁻ to H₂S using sulfur-reducing bacteria(“SRB”). H₂S may supply an energy source to the CAT bioreactor. The SO₄²⁻ produced in the CAT bioreactor may be recycled to generate additionalH₂S in a first bioreactor. Non-extractable fractions may be converted tonutrients to drive the bacterial system and perhaps even supplyessentially all of the nutrient needs. Biomass generated in both the CATand SRB bioreactors can be processed to obtain purified lipids and othersubstances for processing into biodiesel, bioproducts, and othermaterials. Experiments may elucidate data needed to design and establishoperational parameter performance and control values for a bioreactor.The bio-oils may be used as a precursor to synthesize bioproducts andpetroleum replacement products.

Modeling and systems integration can be conducted for large-scale powerplant applications and perhaps even small-scale operations such ascement and fertilizer manufacturing facilities as a “drop in” processinto a conventional biodiesel plant and may even impact of differentamounts of carbon capture on power plant efficiency and costs. Animportant aspect of the deployment project may entail assessing marketpenetration for CAT biodiesel and other end products. Bio-oils can spurseveral domestic industries—a number of transportation fuels and otherchemicals and polymers needed to sustain domestic U.S. industries andinfrastructure assets, such as highways, airport runways, or the like.This may be a dramatically different approach compared to coalgasification for domestic production of such end products. The proposedconcept may represent a transformational pathway to convert CO₂ intopetroleum replacement products such as biodiesel and may even provide anefficient and economical method of capturing CO₂.

Naturally, further objects, goals and embodiments of the inventions aredisclosed throughout other areas of the specification claims.

Detailed Description of Alternative Embodiments of the Invention

As mentioned earlier, the present invention includes a variety ofaspects, which may be combined in different ways. The followingdescriptions are provided to list elements and describe some of theembodiments of the present invention. These elements are listed withinitial embodiments, however it should be understood that they may becombined in any manner and in any number to create additionalembodiments. The variously described examples and preferred embodimentsshould not be construed to limit the present invention to only theexplicitly described systems, techniques, and applications. Further,this description should be understood to support and encompassdescriptions and claims of all the various embodiments, systems,techniques, methods, devices, and applications with any number of thedisclosed elements, with each element alone, and also with any and allvarious permutations and combinations of all elements in this or anysubsequent application.

Embodiments of the present invention may investigate carbon assimilationrates of chemoautotroph bacteria such as sulfur oxidizing bacteria(bacteria that fix inorganic carbon (CO₂) through the oxidation ofchemicals rather than from sunlight). This process may use theseorganisms in a biological carbon capture and conversion system to removecarbon dioxide (CO₂) from utility and industrial facility emissions.

The proposed approach may rely on the concept that synthetic symbiosisbetween sulfur reducing bacteria and sulfur oxidizing bacteria can besustained in a controlled manner with perhaps predictable biomassproduction rates in a specified operating regime. Furthermore, this maybe accomplished through chemical looping of sulfur between sulfurreducing heterotrophs and sulfur oxidizing chemolithioautotrophs. Inaddition, the technical approach may lend itself to tailoring of theoperational conditions for the harvesting of biological lipids and fattyacids perhaps for the purpose of producing biofuels and other petroleumreplacement products. Also, the harvested materials may display uniqueattributes, in that bacteria may produce a wide range of high-valuedbioproducts such as paraffin class hydrocarbons, as well as perhaps evenstandard biodiesel precursor lipids. The non-extractable biomass residuemay be used as the nutrient source for the sulfur-reducing bacteria. Theconcept herein may address the deficiencies of the state of the art byproducing a system that may not be reliant on an uncontrolled source ofenergy for the conversion of CO₂ into biofuels, perhaps even whileproviding a low-cost carbon capture technology for GHG emittingfacilities.

Embodiments of the present invention may address specific societal goalsin that it (1) may enhance economic and energy security of the U.S.through the development of a technology that could produce energy-dense,infrastructure compatible liquid fuels from CO₂ perhaps as the onlycarbon source thereby reducing petroleum imports (2) may effectivelycapture stationary sources of energy-related emissions of greenhousegases (GHG), (3) may improve the energy efficiency of GHG emittingfacilities, such as power generation utilities and industrial andmanufacturing facilities, and perhaps even (4) may ensure that the U.S.could maintain a technological lead in this field. Additionally, theconcept may support many of the goals of the US administration includinginvestment in the next generation of energy technologies, producing moreenergy at home and promoting energy efficiency (by producing biofuelsand bioproducts that store carbon), and perhaps even promoting U.S.competitiveness. As such, the technology can bring about atransformation of the industry, providing a leap in advancement toovercome a number of obstacles that are currently limiting thedeployment of biofuels and carbon capture for retrofitting utility andindustrial GHG facilities for GHG emissions control.

Embodiments of the present invention may include CO₂ removed from a fluegas and injection into an aqueous reactor where carbon-fixing bacteriamay use carbon and incorporate it into their biological tissues andlipids. The process may capture CO₂ using chemoautotrophic bacteria inan anaerobic bioreactor, which may be fueled by H₂S supplied by perhapsa separate bioreactor occupied by perhaps sulfate reducing bacteria(“SRB”). The SO₄ ²⁻ generated as a product of sulfide oxidation in theCAT bioreactor may be used as a source of electron acceptors for makingsulfides (electron donors) in the anaerobic system. The biomass may beharvested from the bioreactor and processed into biofuel and/orpetroleum replacement products. The residual biomass from the oilextraction may be used as the nutrient source for the process. Oilyields may be estimated to be sufficient to provide residual biomass tomeet the nutrient needs of the process.

Biofuels may be currently one of the few commercial alternatives tocontinued dependency on oil. The Energy Independence and Security Act of2007 (EISA) established a goal of 36 billion gallons of biofuels by 2022to power our cars, trucks, jets, ships, mining equipment, locomotivesand tractors. Today only 12 billion gallons of biofuels are producedannually. The EIA's reference case for the 2010 Annual Outlook projectsthat most of the growth in liquid fuel supply will be met bybiofuels—yet EIA also projects that the industry will not meet the 2022goal. The existing biofuels industry represents three generations offuels that in their own right were transformational and marketdisruptive.

The first-generation agricultural-based ethanol biofuels industry hasgrown from 1% of the U.S. fuel supply to 7% in 2008. However, theRenewable Fuel Standard in the EISA has effectively placed a 15 billiongallon cap on ethanol production from corn as part of the new 36 billiongallon target for 2022. The remainder of the target has to be met withsecond and third generation advanced biofuels, including cellulosicethanol, biobutanol, biobased diesel, and other biofuels that are adirect replacement for petroleum-based fuels.

While corn ethanol has played a key role in establishing the U.S.biofuel industry, it remains controversial, due in part to the fact thatusing corn for biofuels displaces crops that would otherwise have beenused for humans, requires high water use, and requires high amounts ofland. Recent estimates are that corn based ethanol has replaced 32% ofthe corn crop in the U.S. for ethanol production.

While cellulosic ethanol may hold great promise, the lack ofcommercial-scale facilities in test or in operation has created a degreeof uncertainty regarding the true operating expenses required forproducing cellulosic ethanol. While cellulosic ethanol istransformational over corn based ethanol, unmodified engines may beunable to process volumetric blends above 10% ethanol withoutsignificant damage. Although Flex Fuel Vehicles (FFVs) enable the driverto choose between using gasoline or ethanol blends up to 85% (E85),market acceptance in the U.S. is very low, since only 1% of U.S. gasstations offer E85 ethanol pumps.

The third-generation of biofuels, based on algae may allow for theproduction of ‘drop-in fuels’ while also making use of the pre-existingpetroleum infrastructure. As such, algae may secrete lipids withchemical compositions similar to petroleum-based hydrocarbons.Algae-based fuels may have growth pattern and harvesting processesqualitatively different from any other alcohol- or oil-producingbiomass. Algae, due to their high oil yield (up to about 50× the amountof biofuel compared to other leading feedstocks), uptake and cycling ofCO₂, and perhaps even capacity to be grown on marginal land in brackishand/or saline water may have spurred its development. Algae may haveyields of about 2,000 gallons per acre per year in open ponds and yieldsmay be increased up to about 10,000 gallons per acre per year, dependingupon the genetically modified organisms (“GMO”) strains that are usedand perhaps even the utilization of photobioreactors (PBRs). However,those strains that produce high yields may also tend to have slowergrowth rates, thereby creating even higher land burdens for production.

The proposed chemoautotrophic-based technologies may be the fourthgeneration biofuel with perhaps equivalent transformational and marketdisruption attributes that the third generation algae-based biofuelsindustry had over the first and second generation ethanol biofuels. Likethird-generation biofuels, the bacteria-based technologies may allow for‘drop in’ fuels that replace and are compatible with petroleum-basedfuels, not solely as an additive. Although CAT based systems may notproduce a very high lipid content, they may have unique compositionsthat may allow for other very high valued other products such asessential equivalent lipid yields with bacteria as with algae.

Due to the fact that CAT based systems do not need sunlight for growth,the land area required for the CAT bacteria growth may be about1/50^(th) the size needed for open algae-based production and may beabout 1/10^(th) the size for algae in photobioreactors that needexpensive energy-consuming artificial lighting. Fourth-generationbio-fuels, due to their smaller footprint, may be more amenable to beco-located with small local and large CO₂ sources, such as power plants.

Biofuels production may not be the only benefit of bacteria-basedsystems. Emerging bacteria-based biofuels production processes may alsobe carbon capture technologies. According to the EIA, the United Statesenergy industry emitted over 5.9 billion metric tonnes of CO₂ in 2006and is projected to emit over 6.4 billion metric tonnes/yr by 2030, an8% increase in emissions. Those fuels with the largest emissions arecoal and oil, with 2.5 and 2.6 billion metric tonnes/year, respectively.As a result of climate change debate, the U.S. is considering mandatoryreductions in CO₂ in incremental stages, as such 5% additional reductionof CO₂ per every 5 years in order to qualify for credits.

Carbon capture and storage (CSS) technologies may be expensive and mayconsume large amounts of parasitic power. The high parasitic power loadwith CCS decreases plant net efficiency from perhaps about 36.8% to onlyabout 24.9%, perhaps resulting in increased CO₂ emissions if power ispurchased to offset the parasitic power. It is important to note thatevery about 1% of net plant efficiency decrease releases another about20 million tons of CO₂ emissions fleet-wide annually. The high capitalof CCS and the parasitic load may result in an increase in cost ofelectricity (COE) of between about 70 and about 80% with ratesincreasing from about 6.4 cents/kWh to about 11.4 cents/kWh.

The value to the power plant of an alternate CCS technology such asbacteria-based capture which may not significantly increase parasiticpower can be calculated from these COE increases. For example, the totalvalue to the utility of about 65% carbon capture on the about 550 MWeplant may result in about 10.4 cents/kWh, based on interpolated DOE'sdata between zero and about 90% percent capture. Assuming values ofabout 8000 hrs of annual plant operation and about 550 MWe net electricoutput, the total additional cost that would be incurred to meet about65% CCS is estimated to be about $176 million annually. Clearly, theimplementation of the proposed CAT bacteria biofuels process couldsignificantly reduce the economic burden of carbon capture on theutility and the ratepayers, but also on the economics of the biofuelsproduced, enhancing energy and environmental security.

There may be an ongoing development in the area of bacteria-basedbiofuels. Although most bacteria generate complex lipid for specifiedchemical production, it has been reported that some bacteria canaccumulate oils under some special conditions. Development of bacteriabased biofuels and other energy related technologies have started togain momentum in industrial applications. Some applications may includesupplementing algae systems during non peak sunlight conditions toperhaps increase production. Other trends in the field include Amery'sfocus on utilizing bacteria as a micro-refinery by feeding the bacteriasugar cane and then ‘milking the microbe’ to secrete synthetic diesel.The microbe (e.g., algae, bacteria and the like) may be a mini-processorof biomass feedstock directly into fuels. Other companies may appear tohave engineered both yeast and E. coli bacteria to make use ofpreviously undiscovered metabolic pathways to convert sugars intohydrocarbon products than can be put straight into your gas tank, orperhaps even sent off to a refinery for processing. This may be nearlycarbon neutral and may be about 65 percent less energy intensive thanethanol fermentation. The utility industry may have studied bacteria forwaste treatment; one successful application is THIOPAQ® technology ownedby a Netherlands company, Paques. This technology may have been adaptedfor sulfur removal from utilities. Chen has demonstrated that methaneproduction may be possible from reverse microbial fuel cell. In thisapplication, the nutrient source may typically be acetate and a voltagemay be applied across the cell to increase and/or perhaps stimulate theoxidation of the nutrient source. Embodiments of the present inventionmay be totally different from these technologies due to its use ofsulfur-based shuttle. Dual bacteria species may be used, the conversionof residue to supply the nutrients needed, (as opposed to use ofexternal waste streams as the nutrient source) and the production ofbiodiesel and other bioproducts are examples of the process differences.

Embodiments of the present invention may include a CAT bacteria biofuelsprocess which may be based on the synthetic symbiosis of bacteria bycreating an energy shuttle through the use of sulfur recycling, whichmay represent a transformational step to the biofuels industry. Biofuelscan be produced from CO₂ sources using chemoautotrophic (CAT) bacteriasuch as Thiobacillus ssp. and sulfur reducing bacteria (SRB) such asDesulfovibrio desulfuricans to form biomass that can be converted tobiofuels.

The microbial processes employed may be derived from two specificcategories, sulfur reducing bacteria (SRB) and sulfur oxidizing bacteria(SOB). Sulfur reducing bacteria may use sulfate or sulfite to oxidizeorganic material for biomass generation, and release sulfides orelemental sulfur. Sulfur oxidizing bacteria (for example, lithotrophs)consume sulfides in combination with inorganic carbon such as CO₂ toproduce biomass and may release sulfates. This process may berepresented by the Calvin cycle and one variant may be depicted in FIG.3. Sulfide may be a known biologic poison, and removal of the sulfidemay stimulate growth of the sulfur reducing bacteria and perhaps eventhe transport of sulfides to the chemolithoautotrophs may supply themwith the needed sulfur for their metabolism. In return thechemolithotrophs may oxidize the sulfide to sulfate or sulfite and it isreturned to the SRB by recycle. Resulting biomass from both bacterialsubsystems may be recovered using standard separation methods and may beprocessed as sources of lipids and paraffin for the production ofpetroleum replacement bio-products. The biomass residue present afterlipid extraction may be used as a nutrient source for the SRBbioreactor.

One embodiment of a conceptual model of the process is provided in FIG.4. Nutrients delivered to the system at Nu1 may provide metabolic carbonto the SRB reactor bacteria. SRB reactor bacteria may convert sulfatesand sulfites into H₂S which may be removed from the reactor through S1.To further enhance the removal of H₂S from the SRB reactor, nitrogen orlow oxygen flue gas can be sparged through inlet SWG1. The sulfide richgas stream may enter the SOB reactor from S1 and may be combined withCO₂ sparged from inlet C1. The CO₂ may be metabolically fixed in thebacteria of the SOB reactor and low CO₂ concentration flue gas may beremoved from the system via outlet C2. During the process of fixingcarbon in the SOB reactor, H₂S may be converted to H₂SO₄ and othersulfates and sulfites. These highly soluble sulfur species may then bereturned to the SRB reactor in a recycle loop S2. Each reaction vesselmay be monitored for pH and additions of buffering solutions may beadded to each reactor through pH1 and pH2, respectively. As biomass mayaccumulate in the given reactors there can come a time when criticalmass has been achieved and the biomass may be ready for harvesting.Harvesting may be accomplished by removal of the biomass laden broththrough B1 and B2 for each reactor respectively and delivering it to theassociated biomass separators. Make up wash water may be delivered toeach reactor through inlets 1 and 3. The biomass separators may be thefirst level biomass stream condensing stage in which the bulk broth maybe removed and recycled through return streams 2 and 4 for each reactorsubsystem. Depending on the separation technique employed, chemicaladdition such as flocculants and surfactants can be added through inletstreams 5 and 6.

Condensed biomass streams B3 and B4 may then be transported to lipid andperhaps even oil extraction equipment perhaps either as individualstream or as combined streams. The CAT system can be dropped into abiofuels production loop as presented in FIG. 5.

CO₂ rich gas may leave the emissions source through flow C1 and may besupplied to the SOB reactor of the CAT system. Gas cleanup units may beinserted in the C1 and C2 flow, and then CO₂ lean gas may be returned tothe emissions source for venting through a stack or even reused in thesystem elsewhere. Condensed biomass streams may be delivered to thebiofuels and petroleum replacement products (PRP) production unit or maybe delivered to a combination of units as perhaps either separate orcombined streams through B1. B2 may convey the bioresidue left overafter lipids and oil extraction to a bioresidue conversion process,where the residue may be broken down into a more readily metabolizednutrient source for microbial activity. Then the converted biomass maybe fed back to the CAT system as nutrients for the SRB reactor. Biofuelsand other PRP may then exit the system to be transported to end usenodes. Water treatment by-products produced during harvesting could beland-filled.

The products extracted from the SRB-CAT bacterial biomass may provideadvantages for processing biofuels. Materials extracted from the biomassmay contain lipids and paraffin. A study conducted by Davis (1968)indicated that the SRB Desulfovibrio desulfuricans contained 5 to 9%lipids with 25% of the lipids consisting of paraffin. Paraffin may be ahigh-valued component used for industrial purposes including synthesisof ozone inhibitors in rubbers and hot climate asphalt additives. Theexpected lipid content of CAT bacteria may be in the range of betweenabout 20 to about 30%. The existence of paraffin in biomass generated bythe CAT bacteria may be a unique part of the CAT biofuels and bioproductprocess. If successful, the concept may leapfrog over today's ethanoland algae approaches perhaps due to its siting flexibility as well asaccommodating large CO₂ sources due to favorable economics with carboncapture credits and its non-reliance on local, dispersed and smallscale-sources of nutrients.

Embodiments of the present invention may have the potential to betransformational in that it may provide a new, highly efficient pathwayfor biofuels production options, that can reduced the nation'sdependence on both domestic and foreign oil perhaps by up to about 64billion barrel crude equivalents annually and can be rapidly deployed. ACAT bacteria-based system may provide the transportation sector with‘drop-in’ fuels, such as biodiesel, aviation fuel, and gasoline perhapsproviding a leap forward in commercial deployment relative to algae. Theuniqueness of the CAT bacterial process may occur in threeareas—process, product, and integration with a CO₂ source.

Embodiments of the present invention may provide a CAT bacteria processwhich may employ a unique shuttling system based on sulfur, which may beabundant on the earth. It may not use any expensive rare earth elementsor perhaps even any organic redox shuttles. Unlike other bacteria-basedsystems that may use metal-containing solids, a CAT bacteria system maybe gas- and liquid phase perhaps avoiding the complications of transferof fine solids in (and between) reactors, which may allow superiormixing and bacteria growth. By replacing solid particle based electronshuttling systems with soluble gases the tendency for biofilm on theshuttle substrate may be eliminated.

In embodiments, a feature of a CAT bacteria concept may employ a dualreactor system with perhaps different bacteria and different conditionsthereby allowing for optimization of each bacteria growth. A system canmodify CO₂ conditions to meet H₂S production in a controlled manner toproduce the optimum production of biomass.

Unlike photosynthesis-based biofuels production process, a CAT-basedprocess may not be driven by photosynthesis. Unlike photosynthesis-basedalgae processes that may capture less or no CO₂ during low lightconditions, thus perhaps complicating their integration with a varietyof CO₂ sources, even with the use of artificial lighting, a CAT bacteriaprocess may provide a controlled and perhaps even constant capture ofCO₂ independent of lighting conditions, thus maximizing yield.

Bacteria can be harvested separately to produce biofuels that may meetindustry specifications and may maximize the recovery of high valuecomponents, such as paraffin or together for lipid yield and biofuelproduction. CAT bacteria produced lipid yields may be comparable toalgae and may be used in petroleum replacement products as well asbiofuels such as biodiesel. The SRB bacteria can produce one quarter ofits extractable mass as paraffins, which may have high value use inozone proofing rubber and as a hot climate asphalt additive.Heterotrophic bacteria may have similar growth rates to algae, perhapsaffording reasonable lipid yields.

The footprint of the CAT bacteria-based system may be projected to belower than ethanol or open algae production systems (acres/ton ofbiomass) perhaps by a factor of about 50 compared to open algaeproduction systems and a factor of about 10 compared with algaephotobioreactors that require external lighting at significant operatingcosts perhaps resulting in less restriction on CAT siting.

A CAT bacteria-based concept can be produced in reasonably sized modulesto meet varying sized CO₂ sources and may be compatible withcommercially available lipid extraction and biodiesel productionprocess, thereby allowing for rapid deployment.

Embodiments of the present invention may be self sufficient with respectto nutrients by converting a non-oil portion of a biomass into nutrientsneeded in the process. Other microbial processes that require externalnutrient sources may be limited in scale due to the quantity of localnutrients available and the infrastructure cost to deliver it to the CO₂source, perhaps restricting potential deployment sites.

In a CAT bacteria-based process, CO₂ can be selectively removed from theflue gas and any remaining flue gas, CO₂ and other flue gas species canbe can be handled through existing plant stack and plant infrastructure(fans), affording easy retrofit.

Unlike open algae systems with high evaporative water losses, theembodiments of the present invention may employ recycling in anessentially closed loop. Makeup water can also be supplied by low rankcoal upgrading processes or even by produced waters from the coalbedmethane and oil and gas production.

The bacteria-based concept may be unique and may offer many attributesmaking it a transformational and market disrupting technology with rapiddevelopment and broad and rapid commercial deployment options.

The bioreactor media and gas conditions may impact the carbonassimilation rates of selected chemoautotrophs and these chemoautotrophsmay impact the product composition related to biofuels and petroleumreplacement products. Other process data needed may includebacteria/strains growth rates, extractable product characteristics,water quality treatment needs, and perhaps even baseline data foroperation of bioreactors.

Species/strains of bacteria for use in the anaerobic sulfur reducingbioreactor and the chemoautotrophic CO₂ capture bioreactor may bedetermined experimentally based on process efficiencies of bacteriaspecies known to perform the required assimilations. Bacteria evaluatedfor use in the sulfur reducing system may include Desulfovibrio ssp. Thechemoautotrophic bacteria evaluated for use in the CO₂ capturebioreactor may include species from three (3) genera, Thiobacillus ssp,Paracoccus ssp, and perhaps even Thiovulum ssp. Thiobacillusdenitrificans may be the primary candidate to be well characterized andmay have been shown to be effective for sulfide oxidation. Other speciesfrom the Thiobacillus genus such as T. thioparus, T. caldus and T.hydrothermalis may also prove to be effective. Several available speciesfrom the Paracoccus and Thiovulum geneses are expected to be effective.

Bioreactors may be used to culture the bacteria to determine perhaps themost prolific species for the capture of CO₂ and reactor sizing. Optimalconditions within the bioreactors can be determined for eachbacteria/strain using a number of environmental variables. Processparameters may be controlled using computer systems equipped to maintainconstant conditions and perhaps to identify small changes in biomassproduction. The impact of nutrient combinations and sources on bacteriapopulations and assimilations can also be determined.

Bacteria cultures for use in the sulfur reducing bioreactor and thechemoautotrophic CO₂ capture bioreactor may be acquired from theAmerican Type Culture Collection (ATCC) bacteria performance/engineeringdesign. Chemoautotrophic bacteria cultures can be evaluated for maximumcarbon fixation rates and perhaps even lipid production based on optimalconditions including but not limited to: temperature, pH, nutrientconcentrations (micro- and macro-nutrients), H₂S concentrations,inorganic carbon concentrations (e.g., CO₂, HCO₃ ⁻ or CO₃ ²⁻ dependingon pH), inorganic ion concentrations, bacterial cell densities, or thelike. Sulfur reducing bacteria can be assessed for maximizing theconversion of SO₄ ²⁻ to H₂S based on optimal environmental conditions inthe bioreactor. Lipids associated with biomass generated by the bacteriamay be quantified and characterized to determine an amount and qualityof extractable product for end-use applications such as biofuels andpetroleum replacement products. Water quality may impact assimilationrates in the bioreactor systems. Tests using a range of soluble saltconcentrations can be conducted using the candidate bacteria/strains.Water exiting the bioreactor can be tested to determine the need fortreatment, particularly when using wastewaters or alternate sources suchas coal bed methane produced waters.

Optimization studies may determine the conditions required to maximizethe production of biomass perhaps using the most prolific bacterium.Deployment may use the highest biomass producers under the mostfavorable environmental conditions identified. Methods can be integratedto improve biomass quantity and quality including but not limited to:(1) harvesting point; (2) optimizing CO₂ incorporation into thebioreactor solution to reach maximum biomass production; and perhapseven (3) the use of an electrical current to improve the kinetics of CO₂assimilation. The biomass may be harvested during an exponential growthphase of the bacteria. An optimal concentration for harvesting bacterialbiomass may be determined experimentally for each of the species/strainof bacteria. Other considerations for optimization may include methodsof injecting CO₂ into the bioreactor solution using either gas sparging(bubbles) or perhaps even membrane infuser systems (microscopicbubbles), such as being developed by Carbon2Algae (C2A). Higher levelsof solution CO₂ may enhance biomass yields to a maximum for eachbacteria/strain evaluated (potentially about 3 to about 5 times higherwith membrane infusers). Another potential optimization agent may beassociated with the use of an electrical current to enhancebio-reactions. The use of electrical current may have been shown toenhance chemoautotrophic bacteria growth rate in an anaerobic system andmay improve oxidation of sulfides in an oxidizing bioreactor resultingin higher assimilation of CO₂ and corresponding increased biomass yield.Electron use by bacteria may not have a direct relationship with sulfatereduction as electrons can reduce SO₄ ⁻² directly without bacterialinvolvement and therefore may be unlikely to improve bio-reactions inthe anaerobic system. Biomass may be harvested from the chemoautotrophicbioreactors at intervals near the peak in the growth phase of thebacteria. The impact of biomass removal on growth rate of the bacteriamay be determined with the objective of establishing the optimum removalpoint that will not detract from the continued pace of CO₂ assimilation.CO₂ can be incorporated into the chemoautotrophic bioreactor usinginjection methods. The rate of CO₂ assimilation can be determined foreach injection method evaluated. The maximum solution concentrations ofCO₂ can be determined along with the corresponding rate of CO₂assimilation.

The conventional method of harvesting the bacteria from the bioreactorsmay be by filtration, followed by a drying step, an oil extraction stepand perhaps even the production of the biodiesel. It may be desirable toassess advanced technologies being developed by others as to theirapplicability to any core chemoautotrphic bacteria carbon capture andbiofuels process. There may be a number of advanced harvestingtechniques that are being developed for other biofuels and otherindustries that may have promise with the process of the embodiments ofthe present invention. Most harvesting methods available for microbialprocess may have been originally developed for animal tissues and plantmaterials. The development of harvesting processes may depend on theconditions of the culture media, nature of the bacteria cells, orperhaps even the type of extract desired. The following process stepsmay be examined: (1) killing or forced dormancy of the bacteria can beachieved by several approaches, including heating, cooling, foaming,addition of chemical agents such as acid, base, sodium hypochlorite,enzymes, or antibiotics; (2) the technologies available to separate thebacteria from the bulk culture media may involve centrifugation, rotaryvacuum filtration, pressure filtration, hydrocycloning, flotation,skimming, and perhaps even sieving. These technologies can be applied inconjunction with other techniques, such as addition of flocculatingagents, or coagulating agents. The relevant parameters to be determinedmay include bacteria size, density and tendency to coalesce into largerflocks; (3) water may need to be removed from the harvested bacteria toprevent the occurrence of lipolysis or perhaps even metabolically thebreakdown of glycerides into free fatty acids within bacteria cells.Various technologies may be used for the drying step, such as perhapsdirect and even indirect methods; and perhaps even (4) after dewatering,the lipids and fatty acids may be separated from the bacterial mass, oreven extracted. It may be important during the extraction to preventauto-oxidative degradation and perhaps even to minimize the presence ofartifacts to ensure high yield of glycerides. Available approaches mayinclude but are not limited to centrifugation, high pressurehomogenization, filtration, as well as solvents such as methanol orethanol extraction. Solvent extraction can be a combination ofmechanical and chemical cell lysis, or cell disruption. Mechanicalmethods of lysis as well as chemical methods and enzymes may also beexamined.

It may be desirable to assess the application of advanced technology forbiodiesel production as well as other bio-products, such as greenplastics. From a chemical point of view, biodiesel may be mainlycomposed of fatty acids mono-alkyl esters. It may be produced fromtriglycerides (the major compounds of oils and fats) with short chainalcohols perhaps via catalytic transesterification as shown in theexample of FIG. 6A. Depending on the type of catalyst adopted, themethods for biodiesel production can be classified as conventional orperhaps even enzyme based. For the former, alkali catalysts, such as KOHand NaOH, with the combination of acid catalyst, such as phosphorusacid, may be used. For the latter, enzyme, such as lipase, may be usedas catalyst. The effort can determine if these techniques are applicableto various embodiments of the present invention. Extracted microbial oilcan also be applied for the production of green plastics includingpackaging films mainly for use as shopping bags, containers and papercoatings, disposable items such as razors, utensils, diapers, cosmeticcontainers and cups, as well as medical surgical garments, upholstery,carpets, packaging, compostable bags and lids or tubs, or the like.Investigations may be performed to explore several factors related toeffective green-plastic production. The quality of resultant greenplastics can be determined through ASTM D6866. The major component ofthe residue may be the cell debris leftover from oil and fatty acidextraction. Like algae, cell debris of the bacteria may containcellulose and perhaps even a variety of glycoproteins. These componentsmay be analyzed and evaluated for end use applications.

Bacteria can be produced from various types of lipid materials,including paraffins and glycerides. In the early stages of bacteriaharvesting, the glyceride, paraffinic, and other lipid materials fromthese processes may require some chemical characterization.Characterization of the glyceride material prior to transesterificationmay be important to help determine the potential yield of the eventualbiodiesel conversion process. This may involve using thin layer orcolumn chromatography to evaluate the polar vs. non-polar lipidscontent. Glyceride lipids may be transesterified with methanol (toperhaps biodiesel), further characterization can be performed using agas chromatography/mass spectrometry techniques to provide a fatty acidtype and distribution for the material. The standardizedcharacterization of biodiesel for use as a transportation fuel mayfollow ASTM method D6751.

Control of dual reactors and perhaps even the resultant products undercontinuous operation may be assessed. These may represent critical itemsfor commercial deployment. In addition, the operational issues such asfouling and perhaps even scaling may need to be known and may beresolved prior to progressing to the next development phase.

Embodiments of the present invention may include a plant design,development and perhaps even validation may consist of integration oftwo bacteria bioreactors and verification of operational parameters. Asystem may be based on two independent bacterial systems perhapsproviding essential sulfur looping to sustain carbon capture at aconstant and predictable rate. It may be desirable to size, determineand optimize operational conditions perhaps to ensure efficient couplingof the systems within the operational regime. Bacterial speciesselection may be key in this effort, perhaps due to the highly specificneeds of individual and consortium bacterial species. Design parametersmay specify fluid stream flow rates and chemical composition for controlof nutrient addition, pH, H₂S recovery and delivery systems, operationaltemperatures for the subsystem reactors, and perhaps even working volumefor desired output parameters for each of the subsystems. Also, thesystem design may consider comparison of state-of-the-art membrane gasinfusion techniques in comparison with traditional gas sparging. Inaddition, techniques developed for harvesting microalgae may beevaluated for bacteria, and may have to be modified accordingly.

Embodiments of the present invention may include but are not limited tovessel sizing, line sizing, input/output identification, systemparameter monitoring specification, and perhaps even biomass densitycalculations. This may include design of H₂S recovery units for thecontrol of toxic H₂S levels in the primary sulfur reducing reactor, andmay even include delivery units for the infusing of H₂S into thesecondary carbon fixing reactor. Also, CO₂ species control through pHand monitoring of these species online and integrated into the controlsystem may be designed. This may involve assigning process control stepsto develop relationships between CO₂ uptake, carbon cycling in thereactor, H₂S to CO₂ uptake, and perhaps even the best source reductionor increase to accomplish these reactions in a controlled manner whilemaximizing carbon conversion. Gas feed to the reaction vessels can bedesigned with the flexibility to evaluate multiple gas sparging andperhaps even membrane based gas infusion technologies. This may includecomparison of existing technologies for extraction of oils from bacteriaand perhaps even determination of the most suitable choice for theapplication, or the development of new technologies to tailor theextraction technique to bacterial applications.

System performance may determine a system's flexibility to evaluateexternal processing techniques such as but not limited to membrane gasinfusion, cyclonic separation of biomass, high pressure homogenizationand perhaps even additional state-of-the-art bacteria based oilextraction techniques, and operational improvements may be evaluated forreducing bio-fouling.

A system startup and shakedown may be completed in several stages. Thesystem may be run with sterile water for operational checks. Next, theseed reactors may be run to provide biomass for analysis to ensure thatthe species may be produced and conform to bench-scale data. Then eachof the large bioreactors may be run independently to ensure workingparameters meet the expected operational regimes. Finally integratedoperation of the combined systems may be performed and operationalconditions determined for steady state operation. Initially operation ofthe seed vessel may focus on the use of traditional gas spargingmethods. A seed vessel may be fitted with state-of-the-art membrane gasinfusion technology and the operational parameters at differentpressure, temperature and nutrient feed rates may be quantified todefine scaling factors for unit operation. The parameters needed torecover the system from an upset in operational conditions may bedetermined, such as a loss in productivity in the sulfur reducingreactor or a sudden change in pH in both tanks as well as perhapsquantifying the system integrity over longer term runs for stability.Biomass may be produced and even recovered using industry standarddewatering techniques and then the effective biomass can be tested foradaptability of algae based oil extraction techniques and the twosub-streams of biomass and oil can be analyzed for acceptability andconformity to bench-scale results. Additional information on bio-foulingcan be evaluated during the production runs and vessel liners toprohibit microbial attachment.

The biodiesel module may be tested to ascertain the performance of thereactor design and reaction control, separator design and control,parameter monitoring, as well as reactor and separator scale-up. Theyield of biodiesel may be compared with the results for the other feedmaterials. The quality of resultant biodiesel can be examined accordingto ASTM D 6751 in terms of flash point, water and sediment, carbonresidue, sulfated ash, density, kinematic viscosity, sulfur, cetanenumber, cloud point, copper corrosion, acid number, free glycerin, totalglycerin, density and perhaps even iodine number; the results can becompared with petroleum diesel fuel.

Embodiments of the present invention may provide CAT based systemintegration and deployment strategies. It may be desirable to assess thescalability of the CAT process using modeling approaches, the efficiencyand cost modeling results for the integration of the CAT process forvarious sized CO₂ sources, an infrastructure/product market assessment,including the impacts of regulations in the CO₂ emissions area and thelegislative initiatives for enhanced biofuels production and anengineering scale-up and perhaps even estimate a pre-commercial-scalemodule of the CAT process.

In order to affect scale-up of the CAT biodiesel/bioproducts productionprocess, the modeling of the system may be necessary. Operational testdata can be used to refine the preliminary model both functionally andquantitatively. In order to understand the commercial transition and theimpact on both the facility supplying the CO₂ and thebiodiesel/bioproducts market, CAT process integration at the CO₂generating site can be conducted. Three scenarios may be addressed: (1)Fossil-fuel fired utility that generates electric power at a nominal 570MW scale and need to be retrofitted with 65% carbon capture; (2)Refinery that may have a CO₂ source, H₂S source and easy integrationinto the refinery products; and perhaps even (3) Industrial-scalefacility, such as cement, lime, or fertilizer manufacturing facility,with a local biodiesel/bioproducts market.

The modeling and system integration can be based on the CAT processmodel performance. The fossil-fuel fired utility case can expand on thepreliminary mass balance as discussed below. The base case power plantmay produce at least about 4 million tons/yr of CO₂ emissions beforeabout 65% capture.

Embodiments of the present invention may address the CAT process as a‘drop in’ biofuels process into a conventional biodiesel plant and mayeven evaluate the impact of different amounts of carbon capture on plantefficiency and costs. The use of the CAT process residue biomass forvarious products as feed for aquaculture and livestock feed and nutrientsource for process can be assessed. A similar analysis of theintegration of the CAT process into a refinery that has a CO₂ source, anH₂S source to perhaps reduce the load requirements for the CAT processand which could provide easy integration into the biocrude refining tovarious refinery products. The model input may use about 4 million tonsof CO₂ as the base refinery input parameter to perhaps study thebioprocess integration with a refinery application and about 65% CO₂capture. In addition, it may be desirable to examine a smaller-scaleapplication such as an industrial-scale cement, lime or fertilizermanufacturing facility, with perhaps a local biodiesel/bioproductsmarket. For the cement plant, a CO₂ emissions of about 0.5 million tonsmay be considered. There are several local markets for biodiesel,including at mines, railroad fueling stations, or even municipality andperhaps even school district markets.

The integration may be based on the biocrude yield from the pilot-scaletests and the quality of biodiesel and other co-produced products. Theconfiguration can also include the use of the bio-residue product as anutrient source or alternatively produce other bioproducts, such asaquaculture and livestock feed supplements.

Embodiments of the present invention may address the system dynamicmodeling for CAT biodiesel market penetration. An example of thestrategy model analysis for CAT biodiesel, modeled after an ethanolmodel by NREL, is presented in FIG. 6B. Following a similar protocol, asimilar model and analysis can be developed and performed for CATbiodiesel. As explained above, there may not be a “one-size-fits-all”solution. CAT biodiesel market penetration can be built upward as in theNREL model (FIG. 6B) from the policy and the external economy basis. Thepolicy space can include government funding opportunities, legislativemandates such as the Renewable Portfolio Standard, low carbon fuel aswell as government (both federal and state) subsidies in the form of taxcredits and perhaps even loan guarantees. The legislative policies mayalso include the impact on the CO₂ source, such as carbon capture andstorage legislation, carbon credits and impact of alternate carboncapture options on parasitic power and cost of electricity. The externaleconomy factors that may include interest rates and price of competingtechnologies may assess the government policies tax credits, andsubsidies. Note that international agreements may also put pressure onthe U.S. to reduce GHG. It may be desirable to examine the supplyinfrastructure, pre-commercial R&D and perhaps even evaluation of theinvestment potential for each type of application. Deployment atindustrial-scale facilities may need a distributed biodieselmarket-based, while larger-scale CO₂ sources siting strategy may allowfor infrastructure compatible fuel distribution. All of these analysiscomponents may be needed to minimize risk for investment and permittingdecisions that allows for commercial deployment.

Embodiments of the present invention may include preliminary evaluationsof the preliminary mass balance for the system, preliminary systemenergy balance, projected composition of the biodiesel that can beproduced from microbial materials, preliminary cost estimates for theCAT bacterial biofuel process, and perhaps even a preliminary massbalance for the system.

A CAT process may involve a symbiosis of two types of bacteria with verydifferent attributes and metabolic requirements. Chemolithotrophicbacteria may have been shown to fix inorganic carbon in conjunction withoxidation of sulfides. When lactate, a relatively common nutrient, maybe used, one possible metabolism is listed as follows:2CH₃CHOHCOO⁻+SO₄ ²⁻→2CH₃CHOO⁻+2HCO₃ ⁻+HS⁻+H⁺ΔG^(o)′=−160 kJ/mol sulfateA possible metabolism for the sulfide oxidation may include:6CO₂+3H₂S+6H₂O→C₆H₁₂O₆+3H₂SO₄ΔG^(o)′=226.8 kJ/mol sulfateIn addition, it has been reported that CO₂ fixing rate at the sulfideoxidation bio-reactor may be 0.132 g CO₂/g Bacteria/hr. In the sulfatereduction bio-reactor, nutrient (lactate) consumption rate may be about2.1 g Lactate/g Bacteria/hr, and sulfate reduction rate may be about 1.2g Sulfate/g Bacteria/hr. This may leads to about 1.9 g Nutrient(lactate) for about 1.0 g CO₂ to be captured.

A schematic of a typical about 570 MWe coal-fired power plant is shownin FIG. 7. Depending on the fuel characteristics, a coal-fired powerplant may emit approximately 4 million tons of CO₂ annually. The plantmay also have a limited amount of SO₂ and NOx emissions that might bebeneficial in a CAT process. FIG. 7 represents the mass balance aroundthe drop-in CAT process integrated into the power plant. CO₂ emissionfrom a 603 MW PRB power plant may be about 1195 Mlb/hr. If it is assumedthat about 65% of CO₂ can be captured by CAT process, around about 1476Mlb/hr nutrient will be needed for the bacteria cultivation according tothe aforementioned calculation, i.e., about 1.9 g Nutrient (lactate) forabout 1.0 g CO₂ to be captured. Assuming that about 95% of CO₂ isconverted to biomass in the bioreactors, biomass production rate can beabout 2140 Mlb/hr, about 30% of which can be used for biodieselproduction. The rest (about 70%), i.e., about 1476 Mlb/hr, can berecycled to the bioreactors as the nutrients through the conversionstep, thereby meeting the system nutrient needs.

In embodiments, to generate about 603 MW of electricity, the PRB coaland air input may be about 633 and about 5038 Mlb/hr, respectively, witha flue gas amount of about 5671 Mlb/hr. After sulfur and ash removal,the amount of cleaned flue gas may be about 4659 Mlb/hr, about 25.6 wt %of which is CO₂, i.e., about 1195 Mlb/hr. Assuming that about 65% of CO₂will be captured by CAT process, about 1476 Mlb/hr nutrients may beneeded for the bacteria cultivation according to the preliminary study,i.e., about 1.9 g nutrient (lactate) for about 1.0 g CO₂ to be captured.Assuming that about 95% biomass conversion in the bioreactors, biomassproduction rate can be about 2140 Mlb/hr, about 30% of which can be usedfor biodiesel production. The rest (about 70%), i.e., about 1476 Mlb/hr,can be recycled to the bioreactors as the nutrients through theconversion step, thereby perhaps eliminating the external nutrientsupply. When other waste nutrients may be available, there may beadditional residue available to partially replace consumption.

Biodiesel can contain no more than about six or about seven fatty acidesters. This renders it possible to estimate the properties of each purecomponent, and then compute the mixture properties based on theavailable mixing rules. The properties of anticipated biodiesel fuel mayexceed industry targets (see Table 1).

TABLE 1 WRI Proposed Targets Component Target Liquid fuel type: dieselfuel, JP-8 51 cetane aviation fuel and/or higher octane Biodiesel Fuelfuels for four-stroke internal combustion engines Anticipated liquidfuel energy density 42 MJ/kg Anticipated liquid fuel heat of 0.06 MJ/kgvaporization Anticipated liquid fuel-energy-out to >63%photon/electrical energy-in of the envisioned system Rare earth elementsor organic redox Economical at distributed shuttles generation,industrial facility and central power plant scales

Nutrients for bacteria cultivation may be about $0.50/kg with thelactate price close to about $0.50/kg. Energy requirements for bacteriaharvesting based on the mechanical methods can be approximately$0.10/kg. For microbial oil extraction, the cost could be around$0.60/kg when methanol is used as extraction solvent with the price maybe about $0.3/kg. The cost for biodiesel production may be about$0.20/kg through the conventional method. It may be important to notethat methanol used for microbial extraction may also serve as the onlyreactant besides bio-oil for the biodiesel production. Thus, total costfor the biodiesel may be about $1.20/kg, or about $3.87/gallon. The costestimation is summarized in Table 2. Similar analyses may be needed forsite specific deployment of the CAT process.

TABLE 2 Estimation of the Production Cost (US$/kg) of Biodiesel fromBacterial-Based Oils Cost Bacteria Bacaterial oil Biodiesel Total coststructure Nutrients harvesting extraction production (per kg) In US$$0.50 $0.10 $0.40 $0.20 $1.20With the expected energy density of biodiesel to be about 42 MJ/kg, thecost of fuel could be about $0.30/MJ, or about $3.0×10⁻⁵/Btu based onabout 1 MJ equal to about 948 BTU.

Biodiesel may generally contain no more than about six or about sevenfatty acid esters enabling estimating the properties of each purecomponent, and then computing the mixture properties based on theavailable mixing rules. No rare earth elements may be used and organicredox shuttles involved may not be easily deployed economically at largescale. Integration with coal fired power plants may enable use of lowgrade thermal energy and may even provide a ready supply of nutrients.

The biodiesel fuel can be a next generation renewable fuels that mayeasily integrate into the U.S. current biofuel refining and distributioninfrastructure at both large central plants and local distributed scaleplants, perhaps while not diverting resources currently utilized forfood production. In fact, one end product can be domestic fertilizer tolower costs for domestic farm livestock and produce production. Theproposed concept may not use photosynthetic autotrophic production. Ifthe over 2.5 billion metric tons of CO₂ emitted in the U.S. each yearfrom coal power plants may be converted to bio-oils and transportationfuels, this technology may present the potential to avoid the netexpenditures for imported crude oil (and petroleum products) estimatedto reach about $377,000,000,000 U.S. dollars by 2030. This may have atremendously positive impact of the U.S. trade deficit, and may be evenbetter if exports result.

The technology may leverage synthetic biology and metabolic engineeringadvances to modify microbiological metabolic pathways and perhaps evendevelop novel biological systems that can directly utilize electrons andreduced metal ions as a source of reducing equivalents for conversion ofCO₂ to liquid fuels. At an overall system efficiency >about 60%, thetechnology may effectively and efficiently convert CO₂ into a dieselfuel. The concept may entail the development of a sulfur-based Calvincycle variant that accepts reducing equivalents from regenerable agentsother than Photosystems I and II or even directly from solar current. Inaddition, the CAT process may be a specifically engineered system andset of bioreactors to provide an ecosystem environment that culturesbacterium and may be self-sustaining resulting in a robust organismengineered ecosystem well suited for commercial scale integration withcoal power plants. This may allow easy access to organisms andbiosynthetic routes to conduct independent, unbiased validation. Thevarious species created may be readily analyzed with existingtechnology. The technology may be forward thinking in that the nutrientsources used for stimulation and augmentation of the biologic growth maybe supplemented with biomass recycling and waste stream organics,perhaps resulting in creative approaches and innovation to design,development, and integrated practical and economically viable productionsystems. By well-engineered integration, the concept may maximize energyand water conservation, may maximize efficiency and may even minimizecosts. Further the system and major components may be well-knownequipment within various industry sectors making it scalable, robust,and perhaps even relatively straightforward to maintain and operate bytraditional skilled workforce with only minor training.

As can be easily understood from the foregoing, the basic concepts ofthe present invention may be embodied in a variety of ways. It involvesboth biological conversion techniques as well as devices to accomplishthe appropriate biological converter. In this application, thebiological conversion techniques are disclosed as part of the resultsshown to be achieved by the various devices described and as steps whichare inherent to utilization. They are simply the natural result ofutilizing the devices as intended and described. In addition, while somedevices are disclosed, it should be understood that these not onlyaccomplish certain methods but also can be varied in a number of ways.Importantly, as to all of the foregoing, all of these facets should beunderstood to be encompassed by this disclosure.

The discussion included in this application is intended to serve as abasic description. The reader should be aware that the specificdiscussion may not explicitly describe all embodiments possible; manyalternatives are implicit. It also may not fully explain the genericnature of the invention and may not explicitly show how each feature orelement can actually be representative of a broader function or of agreat variety of alternative or equivalent elements. Again, these areimplicitly included in this disclosure. Where the invention is describedin device-oriented terminology, each element of the device implicitlyperforms a function. Apparatus claims may not only be included for thedevice described, but also method or process claims may be included toaddress the functions the invention and each element performs. Neitherthe description nor the terminology is intended to limit the scope ofthe claims that will be included in any subsequent patent application.

It should also be understood that a variety of changes may be madewithout departing from the essence of the invention. Such changes arealso implicitly included in the description. They still fall within thescope of this invention. A broad disclosure encompassing both theexplicit embodiment(s) shown, the great variety of implicit alternativeembodiments, and the broad methods or processes and the like areencompassed by this disclosure and may be relied upon when drafting theclaims for any subsequent patent application. It should be understoodthat such language changes and broader or more detailed claiming may beaccomplished at a later date (such as by any required deadline) or inthe event the applicant subsequently seeks a patent filing based on thisfiling. With this understanding, the reader should be aware that thisdisclosure is to be understood to support any subsequently filed patentapplication that may seek examination of as broad a base of claims asdeemed within the applicant's right and may be designed to yield apatent covering numerous aspects of the invention both independently andas an overall system.

Further, each of the various elements of the invention and claims mayalso be achieved in a variety of manners. Additionally, when used orimplied, an element is to be understood as encompassing individual aswell as plural structures that may or may not be physically connected.This disclosure should be understood to encompass each such variation,be it a variation of an embodiment of any apparatus embodiment, a methodor process embodiment, or even merely a variation of any element ofthese. Particularly, it should be understood that as the disclosurerelates to elements of the invention, the words for each element may beexpressed by equivalent apparatus terms or method terms—even if only thefunction or result is the same. Such equivalent, broader, or even moregeneric terms should be considered to be encompassed in the descriptionof each element or action. Such terms can be substituted where desiredto make explicit the implicitly broad coverage to which this inventionis entitled. As but one example, it should be understood that allactions may be expressed as a means for taking that action or as anelement which causes that action. Similarly, each physical elementdisclosed should be understood to encompass a disclosure of the actionwhich that physical element facilitates. Regarding this last aspect, asbut one example, the disclosure of a “reactor” should be understood toencompass disclosure of the act of “reacting”—whether explicitlydiscussed or not—and, conversely, were there effectively disclosure ofthe act of “reacting”, such a disclosure should be understood toencompass disclosure of a “reactor” and even a “means for reacting.”Such changes and alternative terms are to be understood to be explicitlyincluded in the description.

Any patents, publications, or other references mentioned in thisapplication for patent are hereby incorporated by reference. Anypriority case(s) claimed by this application is hereby appended andhereby incorporated by reference. In addition, as to each term used itshould be understood that unless its utilization in this application isinconsistent with a broadly supporting interpretation, common dictionarydefinitions should be understood as incorporated for each term and alldefinitions, alternative terms, and synonyms such as contained in theRandom House Webster's Unabridged Dictionary, second edition are herebyincorporated by reference. Finally, all references listed below or otherinformation statement filed with the application are hereby appended andhereby incorporated by reference, however, as to each of the above, tothe extent that such information or statements incorporated by referencemight be considered inconsistent with the patenting of this/theseinvention(s) such statements are expressly not to be considered as madeby the applicant(s).

U.S. PATENT APPLICATION PUBLICATIONS

Name of Patentee Publication Publication or Applicant of Number Datecited Document 20100120104 A1 2010 May 13 Reed

NON-PATENT LITERATURE DOCUMENTS

Akoh, C. C., S. Chang, G. Lee and J. Shaw, “Enzymatic approach tobiodiesel production,” J. Agric. Food Chem., 55, 8995-9005, 2007.Antoni, D., V. V. Zverlov, and W. H. Schwarz, “Biofuels from microbes,”Appl. Microbiol. Biot., 77, 23-35, 2007. Bland, A., J. Newcomer, T.Zhang, K. Sellakumar, “Pilot testing of WRI's novel mercury controltechnology by recombustion thermal treatment of coal”, Report to U.S.Department of Energy, Contract No. DE-FC26-98FT40323 Task 79, June 2009.Certick, M. and S. Shimizu, “Review: biosynthesis and regulation ofmicrobial polyunsaturated fatty acid production,” J. Biosci. Bioeng.,87, 1-14, 1999. Certik, M. and R. Horenitzky, “Supercritical CO2extraction of fungal oil containing y-linolenic acid,” Biotechnol.Tech., 13, 11-15, 1999. Chen, G., “A microbial polyhydroxyalkanoates(PHA) based bio- and materials industry,” Chem. Soc. Rev., 38,2434-2446, 2009. Ciferno, J., “Pulverized coal oxycombustion powerplants - final results” (revised), U.S. Department of Energy, NationalEnergy Technology Laboratory, Nov. 1, 2007. Cooney, M. J., E. Roschi, I.W. Marison, C. Comninellis, and U. Von Stockar, “Physiologic studieswith the sulfate reducing bacterium Desulfovibrio desulfuricans:Evaluation for use in a biofuel cell,” Enzym. Microb. Tech., 8, 358-365,1996. Dasu, B. N., and K. L. Sublette, “Microbial Removal of sulfurdioxide from a gas stream with net oxidation to sulfate,” Appl. Biochem.Biotech., Vol 20/21, 207-220, 1989. Davis, J. B., “Paraffinichydrocarbons in the sulfate reducing bacterium Desulfovibriodesulfuricans,” Chem. Geol., 3, 155-160, 1968. Demirbas, Ayhan,“Sustainable cofiring of biomass with coal,” Energy Conversion andManagement, Vol 44, 1465-1479 Dhar, B. R., and K. Kirtania, “Excessmethanol recovery in biodiesel production process using a distillationcolumn: a simulation study,” Chemical Engineering Research Bulletin, 13,45-50, 2009. DOE/NETL, “Cost and performance baseline for fossil energyplants-Vol. 1: bituminous coal and natural gas to electricity,”DOE/NETL-2007/1281, May 2007, Revision 1, August 2007. Garces, R., R.Alvarez-Ortega, E. Martinez-Force, S. Cantisan, “Lipid characterizationin vegetative tissues of high saturated fatty acid sunflower mutants,”J. Agric. Food Chem., 47, 78-82, 1999. Green Econometrics,“Understanding the cost of solar energy,”http://greenecon.net/understanding-the-cost-ofsolarenergy/energy_economics.html, 2007. GTM Research, “Transitioningfrom 1st generation to advanced biofuels,” a white paper from EnterpriseFlorida and GTM Research, February 2010. Howard, E. E., “Systems andmethods for large-scale production and harvesting of oil-rich algae,”PCT/US2007/006466, WO2007/109066 A1. Kadam, K. L., “Environmentalimplications of power generation via coal-microalgae cofiring,” Energy,Vol 27, 905-922, 2002. Kelly, D. P, “Thermodynamic aspects of energyconservation by chemolithotrophic sulfur bacteria in relation to thesulfur oxidation pathways,” Arch Microbial, 171, 219-229, 1999 Li, Q.,W. Du, and D. Liu, “Perspectives of microbial oils for biodieselproduction,” Appl. Microbiol. Biot., 80, 749-756, 2008. Mona, K. G., H.O. Sanaa, and M. A. Linda, “Single cell oil production by Gordonia spp.DG using agro-industrial wastes,” World J. Microbiol. Biotechnol., 24,1703-1711, 2008. Monteiro, M. R., A. R. P. Ambrozin, L. M. Liao, and A.G. Ferreira, “Critical review on analytical methods for biodieselcharacterization,” Talanta, 77, 593-605, 2008, Parawira, W.,“Biotechnological production of biodiesel fuel using biocatalyzedtransesterification: A review,” Cr. Rev. Biotechn., 29, 82-93, 2009.Rabus, R., T. A. Hansen and F. Widdel, “Dissimilatory sulfate- andsulfur-reducing prokaryotes,” Prokaryotes, 2, 659-768, 2006. Scott, K.M., and C. M. Cavanaugh, “CO2 uptake and fixation by endosymbioticchemoautotrophs from the bivalve Solemya velum,” Appl. Environ. Microb.,73, 1174-1179, 2007. Shively, J. M., G. van Keulen, and W. G. Meijer,“Something from almost nothing: carbon dioxide fixation inchemoautotrophs,” Annu. Rev. Microbiol, 52, 191-230, 1998. Thurmond, W.,Algae 2020: Algal Biofuels Demand Drivers, Players, Business Models,Markets & Commercialization Outlook, 1st edition, 2009,www.emerging-market.com. van Lier, R. J. M., C. J. N. Buisman, and N. L.Piret, “THIOPAQ ® technology: versatile high-rate biotechnology for themining and metallurgical industries,” Proceedings of the TMS FallExtraction and Processing Conference, v 3, p 2319-2328, 1999. Yuan, W.,A. C. Hansen, and Q. Zhang, “Predicting the physical properties ofbiodiesel for combustion modeling,” T. ASAE, 46, 1487-1493, 2003. Zhang,T., and L. T. Fan, “Significance of dead-state-based thermodynamics indesigning a sustainable process,” Design for Energy and theEnvironment - Proceedings of the Seventh International Conference on theFoundations of Computer-Aided Process Design, Eds., M. M. El-Halwagi andA. A. Linninger, CRC Press, Boca Raton, FL, pp. 233-241, 2010. Zhang,X., R. Luo, Z. Wang, Y. Deng, and G. Chen, “Application of(R)-3-hydroxyalkanoate methyl esters derived from microbialpolyhydroxyalkanoates as novel biofuels,” Biomacromolecules, 10,707-711, 2009.

Thus, the applicant(s) should be understood to have support to claim andmake a statement of invention to at least: i) each of the biologicalconversion devices as herein disclosed and described, ii) the relatedmethods disclosed and described, iii) similar, equivalent, and evenimplicit variations of each of these devices and methods, iv) thosealternative designs which accomplish each of the functions shown as aredisclosed and described, v) those alternative designs and methods whichaccomplish each of the functions shown as are implicit to accomplishthat which is disclosed and described, vi) each feature, component, andstep shown as separate and independent inventions, vii) the applicationsenhanced by the various systems or components disclosed, viii) theresulting products produced by such systems or components, ix) eachsystem, method, and element shown or described as now applied to anyspecific field or devices mentioned, x) methods and apparatusessubstantially as described hereinbefore and with reference to any of theaccompanying examples, xi) the various combinations and permutations ofeach of the elements disclosed, xii) each potentially dependent claim orconcept as a dependency on each and every one of the independent claimsor concepts presented, and xiii) all inventions described herein.

With regard to claims whether now or later presented for examination, itshould be understood that for practical reasons and so as to avoid greatexpansion of the examination burden, the applicant may at any timepresent only initial claims or perhaps only initial claims with onlyinitial dependencies. The office and any third persons interested inpotential scope of this or subsequent applications should understandthat broader claims may be presented at a later date in this case, in acase claiming the benefit of this case, or in any continuation in spiteof any preliminary amendments, other amendments, claim language, orarguments presented, thus throughout the pendency of any case there isno intention to disclaim or surrender any potential subject matter. Itshould be understood that if or when broader claims are presented, suchmay require that any relevant prior art that may have been considered atany prior time may need to be re-visited since it is possible that tothe extent any amendments, claim language, or arguments presented inthis or any subsequent application are considered as made to avoid suchprior art, such reasons may be eliminated by later presented claims orthe like. Both the examiner and any person otherwise interested inexisting or later potential coverage, or considering if there has at anytime been any possibility of an indication of disclaimer or surrender ofpotential coverage, should be aware that no such surrender or disclaimeris ever intended or ever exists in this or any subsequent application.Limitations such as arose in Hakim v. Cannon Avent Group, PLC, 479 F.3d1313 (Fed. Cir 2007), or the like are expressly not intended in this orany subsequent related matter. In addition, support should be understoodto exist to the degree required under new matter laws—including but notlimited to European Patent Convention Article 123(2) and United StatesPatent Law 35 USC 132 or other such laws—to permit the addition of anyof the various dependencies or other elements presented under oneindependent claim or concept as dependencies or elements under any otherindependent claim or concept. In drafting any claims at any time whetherin this application or in any subsequent application, it should also beunderstood that the applicant has intended to capture as full and broada scope of coverage as legally available. To the extent thatinsubstantial substitutes are made, to the extent that the applicant didnot in fact draft any claim so as to literally encompass any particularembodiment, and to the extent otherwise applicable, the applicant shouldnot be understood to have in any way intended to or actuallyrelinquished such coverage as the applicant simply may not have beenable to anticipate all eventualities; one skilled in the art, should notbe reasonably expected to have drafted a claim that would have literallyencompassed such alternative embodiments.

Further, if or when used, the use of the transitional phrase“comprising” is used to maintain the “open-end” claims herein, accordingto traditional claim interpretation. Thus, unless the context requiresotherwise, it should be understood that the term “comprise” orvariations such as “comprises” or “comprising”, are intended to implythe inclusion of a stated element or step or group of elements or stepsbut not the exclusion of any other element or step or group of elementsor steps. Such terms should be interpreted in their most expansive formso as to afford the applicant the broadest coverage legally permissible.

Finally, any claims set forth at any time are hereby incorporated byreference as part of this description of the invention, and theapplicant expressly reserves the right to use all of or a portion ofsuch incorporated content of such claims as additional description tosupport any of or all of the claims or any element or component thereof,and the applicant further expressly reserves the right to move anyportion of or all of the incorporated content of such claims or anyelement or component thereof from the description into the claims orvice-versa as necessary to define the matter for which protection issought by this application or by any subsequent continuation, division,or continuation-in-part application thereof, or to obtain any benefitof, reduction in fees pursuant to, or to comply with the patent laws,rules, or regulations of any country or treaty, and such contentincorporated by reference shall survive during the entire pendency ofthis application including any subsequent continuation, division, orcontinuation-in-part application thereof or any reissue or extensionthereon.

What is claimed is:
 1. A method of reducing carbon dioxide pollutantsemitted from industrial plants comprising the steps of: providing anindustrial system which releases emissions into the atmosphere, saidemissions having at least some carbon dioxide emissions; providing adual reactor emission reduction system comprising: a first ex-situprocessing reactor containing chemoautotrophic bacteria connected to asecond ex-situ processing reactor containing sulfate reducing bacteria,whereby said chemoautotrophic bacteria are capable of digesting carbondioxide fueled by reduced sulfur compounds to generate oxidized sulfurcompounds, and whereby said sulfate reducing bacteria are capable ofconverting said oxidized sulfur compounds to generate said reducedsulfur compounds; a sulfur shuttle between said first and second ex-situprocessing reactors; incorporating said dual reactor emission reductionsystem into said industrial system; capturing substantially all of saidemissions; pretreating said emissions to provide separated carbondioxide emissions; containing said separated carbon dioxide emissions;introducing said separated carbon dioxide emissions into said firstex-situ processing reactor of said dual reactor emission reductionsystem; digesting said separated carbon dioxide emissions with saidchemoautotrophic bacteria; shuttling said oxidized sulfur compounds tosaid sulfate reducing bacteria in said second ex-situ processingreactor; shuttling said reduced sulfur compounds to saidchemoautotrophic bacteria in said first ex-situ processing reactor tocreate a continuous energy supply to said chemoautotrophic bacteria andsaid sulfate reducing bacteria; regulating said first and second ex-situprocessing reactors; biologically producing biomass, lipids, andparaffin in said first and second ex-situ processing reactors;extracting said biomass, lipids and paraffin from said reactors; andreducing said carbon dioxide emissions into said atmosphere from saidindustrial system.
 2. A method of reducing carbon dioxide pollutantsaccording to claim 1 wherein said emissions further comprise a pollutantselected from a group consisting of nitrogen, nitrogen oxide, sulfuroxide, oxygen, and any combination thereof.
 3. A method of reducingcarbon dioxide pollutants according to claim 1 wherein said industrialsystem is selected from a group consisting of power generation sources,cement producing plants, coal refineries, oil refineries, refineries,lime producing plants, non-power generation sources, coal-fired powerplants, natural gas-fired power plants, generation fuel cells, andcombustion power plants.
 4. A method of reducing carbon dioxidepollutants according to claim 1 wherein said chemoautotrophic bacteriaare selected from a group consisting of Thiobacillus species, Paracoccusspecies, and combinations thereof.
 5. A method of reducing carbondioxide pollutants according to claim 1 and further comprising the stepof providing waste organic carbon to said sulfate reducing bacteria insaid second ex-situ processing reactor.
 6. A method of reducing carbondioxide pollutants according to claim 5 wherein said waste organiccarbon is selected from a group consisting of waste dairy products,returned milk, waste dairy byproducts, cheese whey, straw, andwoodchips.
 7. A method of reducing carbon dioxide pollutants accordingto claim 1 wherein said sulfate reducing bacteria comprisesDesulfovibrio desulfuricans and wherein said chemoautotrophic bacteriais selected from a group consisting of Thiobacillus ssp. genus,Paracoccus ssp genus, Thiovulum ssp. genus, Thiobacillus denitrificans,T. thioparus, T. caldus, T. hydrothermalis, Paracoccus genus, andThiovulim genus.
 8. A method of reducing carbon dioxide pollutantsaccording to claim 1 and further comprising the step of providingrecycled process biomass residue from said dual reactor emissionreduction system as an electron donor supply to said sulfate reducingbacteria in said second ex-situ processing reactor.
 9. A method ofreducing carbon dioxide pollutants according to claim 1 and furthercomprising the step of processing said biomass into a fuel.
 10. A methodof reducing carbon dioxide pollutants according claim 1 and furthercomprising the step of drying said biomass.
 11. A method of reducingcarbon dioxide pollutants according to claim 1 wherein said step ofregulating said first and second ex-situ processing reactors comprises astep selected from a group consisting of: adjusting a pH of said firstor second ex-situ processing reactors; adding buffering solutions tosaid first or second ex-situ processing reactors; adjusting atemperature of said first or second ex-situ processing reactors; addingnutrients to said first or second ex-situ processing reactors; addinginorganic ions to said first or second ex-situ processing reactors;adjusting inorganic ions concentrations in said first or second ex-situprocessing reactors; adjusting bacterial cell densities in said first orsecond ex-situ processing reactors; and adjusting nutrientconcentrations added to said first or second ex-situ processingreactors.
 12. A method of reducing carbon dioxide pollutants accordingto claim 1 wherein said step of regulating said first and second ex-situprocessing reactors comprises a step selected from a group consistingof: adjusting a concentration of said oxidized sulfur compounds enteringsaid second ex-situ processing reactor; adjusting a concentration ofsaid reduced sulfur compounds entering said first ex-situ processingreactor; and adjusting a concentration of separated carbon dioxideemissions entering said first ex-situ processing reactor.
 13. A methodof reducing carbon dioxide pollutants according to claim 1 wherein saidoxidized sulfur compounds comprise sulfate.
 14. A method of reducingcarbon dioxide pollutants according to claim 1 wherein said reducedsulfur compounds comprise hydrogen sulfide.
 15. A method of reducingcarbon dioxide pollutants according to claim 1 wherein said step ofextracting said biomass from said reactors comprises the step ofextracting said biomass when a critical mass of biomass has beenachieved.
 16. A method of reducing carbon dioxide pollutants accordingto claim 1 wherein said step of incorporating said dual reactor emissionreduction system into said industrial system comprises the step ofretrofitting said dual reactor emission reduction system into saidindustrial system.